<template>
  <div class="canvasBox">
    <template v-if="isUse">
      <div class="box">
        <div class="line"></div>
        <div class="angle"></div>
      </div>
      <div class="box2" v-if="isUseTorch">
        <div class="track" @click="openTrack">
          <svg t="1653920715959" class="icon" divBox="0 0 1024 1024" version="1.1" xmlns="http://www.w3.org/2000/svg"
            p-id="1351" width="32" height="32">
            <path
              d="M651.353043 550.479503H378.752795L240.862609 364.315031c-3.688944-4.897391-5.660621-10.876025-5.660621-17.045466v-60.040745c0-15.773416 12.847702-28.621118 28.621118-28.621118h502.459627c15.773416 0 28.621118 12.847702 28.621118 28.621118v59.977143c0 6.105839-1.971677 12.084472-5.660621 17.045466l-137.890187 186.228074zM378.752795 598.308571v398.024348c0 15.328199 12.402484 27.667081 27.667081 27.667081h217.266087c15.328199 0 27.667081-12.402484 27.66708-27.667081V598.308571H378.752795z m136.300124 176.942112c-14.564969 0-26.331429-11.76646-26.331428-26.331428v-81.283975c0-14.564969 11.76646-26.331429 26.331428-26.331429 14.564969 0 26.331429 11.76646 26.331429 26.331429v81.283975c0 14.564969-11.76646 26.331429-26.331429 26.331428zM512 222.608696c-17.554286 0-31.801242-14.246957-31.801242-31.801243V31.801242c0-17.554286 14.246957-31.801242 31.801242-31.801242s31.801242 14.246957 31.801242 31.801242v159.006211c0 17.554286-14.246957 31.801242-31.801242 31.801243zM280.932174 205.881242c-9.47677 0-18.889938-4.197764-25.122981-12.275279L158.242981 67.991056a31.864845 31.864845 0 0 1 5.597019-44.648944 31.864845 31.864845 0 0 1 44.648944 5.597018l97.502609 125.551305a31.864845 31.864845 0 0 1-5.597019 44.648944c-5.787826 4.579379-12.656894 6.741863-19.46236 6.741863zM723.987081 205.881242c-6.805466 0-13.674534-2.162484-19.462361-6.678261a31.794882 31.794882 0 0 1-5.597018-44.648944l97.566211-125.551304a31.794882 31.794882 0 0 1 44.648944-5.597019 31.794882 31.794882 0 0 1 5.597019 44.648944l-97.566211 125.551305c-6.360248 8.077516-15.709814 12.27528-25.186584 12.275279z"
              fill="#ffffff" p-id="1352"></path>
          </svg>
          {{ trackStatus ? '关闭闪光灯' : '打开闪光灯' }}
        </div>
      </div>

      <div class="mask1 mask" :style="'height:' + maskHeight + 'px;'"></div>
      <div class="mask2 mask"
        :style="'width:' + maskWidth + 'px;top:' + maskHeight + 'px;height:' + canvasHeight + 'px'"></div>
      <div class="mask3 mask" :style="'height:' + maskHeight + 'px;'"></div>
      <div class="mask4 mask"
        :style="'width:' + maskWidth + 'px;top:' + maskHeight + 'px;height:' + canvasHeight + 'px'"></div>
    </template>
    <template v-else>
      <slot name="error">
        <div class="error">
          <div class="on1">相机权限被拒绝，请尝试如下操作：</div>
          <div>· 刷新页面后重试；<button onclick="window.location.reload()">点击刷新</button></div>
          <div>· 检查相机权限是否被禁用；</div>
          <div>· 若均无效，请联系负责人录入签到；</div>
        </div>
      </slot>
    </template>
  </div>
</template>

<script>
  import jsQR from 'jsQR'

  export default {
    props: {
      continue: {
        type: Boolean,
        default: false // false 监听一次   true 持续监听
      },
      exact: {
        type: String,
        default: 'environment' // environment 后摄像头  user 前摄像头
      },
      size: {
        type: String,
        default: 'whole' // whole 全屏  balf 半屏
      },
      definition: {
        type: Boolean,
        default: true // fasle 正常  true 高清
      }
    },
    data() {
      return {
        windowWidth: 0,
        windowHeight: 0,
        video: null,
        canvas2d: null,
        canvas2d2: null,
        canvasWidth: 200,
        canvasHeight: 200,
        maskWidth: 0,
        maskHeight: 0,
        inter: 0,

        track: null,
        isUseTorch: false,
        trackStatus: false,

        isParse: false,
        isUse: true
      }
    },
    mounted() {
      if (origin.indexOf('https') === -1) throw '请在 https 环境中使用摄像头组件。'

      this.windowWidth = document.documentElement.clientWidth || document.body.clientWidth
      this.windowHeight = document.documentElement.clientHeight || document.body.clientHeight
      this.windowHeight = this.size === 'whole' ? this.windowHeight : this.windowHeight / 2
      this.isParse = true

      this.$nextTick(() => {
        this.createMsk()
        this.openScan()
      })
    },
    destroyed() {
      this.closeCamera()
    },
    methods: {
      openScan() {
        const width = this.transtion(this.windowHeight)
        const height = this.transtion(this.windowWidth)
        const videoParam = {
          audio: false,
          video: {
            facingMode: {
              exact: this.exact
            },
            width,
            height
          }
        }
        navigator.mediaDevices
          .getUserMedia(videoParam)
          .then(stream => {
            this.video = document.createElement('video')
            this.video.width = this.windowWidth
            this.video.height = this.windowHeight

            const canvas = document.createElement('canvas')
            canvas.id = 'canvas'
            canvas.width = this.transtion(this.canvasWidth)
            canvas.height = this.transtion(this.canvasHeight)
            canvas.style = 'display:none;'
            //canvas.style = 'position: fixed;top: 0;z-index: 999;left:0'
            this.canvas2d = canvas.getContext('2d')

            // 设置当前宽高 满屏
            const canvasBox = document.querySelector('.canvasBox')
            canvasBox.append(this.video)
            canvasBox.append(canvas)
            canvasBox.style = `width:${this.windowWidth}px;height:${this.windowHeight}px;`

            // 创建第二个canvas
            const canvas2 = document.createElement('canvas')
            canvas2.id = 'canvas2'
            canvas2.width = this.canvasWidth
            canvas2.height = this.canvasHeight
            canvas2.style = 'position: absolute;top: 50%;left: 50%;z-index: 20;transform: translate(-50%, -50%);'
            this.canvas2d2 = canvas2.getContext('2d')
            canvasBox.append(canvas2)

            this.video.srcObject = stream
            this.video.setAttribute('playsinline', true)
            this.video.play()
            this.tick()

            this.track = stream.getVideoTracks()[0]
            setTimeout(() => {
              this.isUseTorch = this.track.getCapabilities().torch || null
            }, 500)
          })
          .catch(err => {
            this.isUse = false
            this.$emit('error', err)
          })
      },

      closeCamera() {
        this.isParse = false
        if (this.video && this.video.srcObject) {
          this.video.srcObject.getTracks().forEach(track => {
            track.stop()
          })
        }
      },

      tick() {
        if (!this.isParse) return
        if (this.video.readyState === this.video.HAVE_ENOUGH_DATA) {
          this.canvas2d.drawImage(
            this.video,
            this.transtion(this.maskWidth),
            this.transtion(this.maskHeight),
            this.transtion(200),
            this.transtion(200),
            0,
            0,
            this.transtion(this.canvasWidth),
            this.transtion(this.canvasHeight)
          )

          const imageData = this.canvas2d.getImageData(
            0,
            0,
            this.transtion(this.canvasWidth),
            this.transtion(this.canvasHeight)
          )

          const code = jsQR(imageData.data, imageData.width, imageData.height, {
            inversionAttempts: 'dontInvert'
          })

          this.canvas2d2.clearRect(0, 0, this.canvasWidth, this.canvasHeight)
          if (code) {
            this.drawLine(code.location.topLeftCorner, code.location.topRightCorner)
            this.drawLine(code.location.topRightCorner, code.location.bottomRightCorner)
            this.drawLine(code.location.bottomRightCorner, code.location.bottomLeftCorner)
            this.drawLine(code.location.bottomLeftCorner, code.location.topLeftCorner)
            if (code.data) {
              this.getData(code.data)
            }
          }
        }
        requestAnimationFrame(this.tick)
      },
      drawLine(begin, end, color = '#FF3B58') {
        this.canvas2d2.beginPath()
        this.canvas2d2.moveTo(this.nutranstion(begin.x), this.nutranstion(begin.y))
        this.canvas2d2.lineTo(this.nutranstion(end.x), this.nutranstion(end.y))
        this.canvas2d2.lineWidth = 4
        this.canvas2d2.strokeStyle = color
        this.canvas2d2.stroke()
      },

      getData(data) {
        alert(data)
        this.$emit('success', data)
        if (!this.continue) {
          // this.closeCamera()
        }
      },

      openTrack() {
        this.trackStatus = !this.trackStatus
        this.track.applyConstraints({
          advanced: [{
            torch: this.trackStatus
          }]
        })
      },

      createMsk() {
        this.maskWidth = this.windowWidth / 2 - this.canvasWidth / 2
        this.maskHeight = this.windowHeight / 2 - this.canvasHeight / 2
      },

      transtion(number) {
        return this.definition ? number * 2.8 : number * 1.8
      },
      nutranstion(number) {
        return this.definition ? number / 2.8 : number / 1.8
      }
    }
  }
</script>

<style scoped>
  page {
    background-color: #333333;
  }

  .canvasBox {
    width: 100vw;
    height: 100vh;
    position: relative;

    background-image: linear-gradient(0deg,
        transparent 24%,
        rgba(32, 255, 77, 0.1) 25%,
        rgba(32, 255, 77, 0.1) 26%,
        transparent 27%,
        transparent 74%,
        rgba(32, 255, 77, 0.1) 75%,
        rgba(32, 255, 77, 0.1) 76%,
        transparent 77%,
        transparent),
      linear-gradient(90deg,
        transparent 24%,
        rgba(32, 255, 77, 0.1) 25%,
        rgba(32, 255, 77, 0.1) 26%,
        transparent 27%,
        transparent 74%,
        rgba(32, 255, 77, 0.1) 75%,
        rgba(32, 255, 77, 0.1) 76%,
        transparent 77%,
        transparent);
    background-size: 3rem 3rem;
    background-position: -1rem -1rem;
    z-index: 10;
    background-color: #1110;
  }

  .box {
    width: 200px;
    height: 200px;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    overflow: hidden;
    border: 0.1rem solid rgba(0, 255, 51, 0.2);
    z-index: 11;
  }

  .line {
    height: calc(100% - 2px);
    width: 100%;
    background: linear-gradient(180deg, rgba(0, 255, 51, 0) 43%, #00ff33 211%);
    border-bottom: 3px solid #00ff33;
    transform: translateY(-100%);
    animation: radar-beam 2s infinite alternate;
    animation-timing-function: cubic-bezier(0.53, 0, 0.43, 0.99);
    animation-delay: 1.4s;
  }

  .box:after,
  .box:before,
  .angle:after,
  .angle:before {
    content: '';
    display: block;
    position: absolute;
    width: 3vw;
    height: 3vw;
    z-index: 12;
    border: 0.2rem solid transparent;
  }

  .box:after,
  .box:before {
    top: 0;
    border-top-color: #00ff33;
  }

  .angle:after,
  .angle:before {
    bottom: 0;
    border-bottom-color: #00ff33;
  }

  .box:before,
  .angle:before {
    left: 0;
    border-left-color: #00ff33;
  }

  .box:after,
  .angle:after {
    right: 0;
    border-right-color: #00ff33;
  }

  @keyframes radar-beam {
    0% {
      transform: translateY(-100%);
    }

    100% {
      transform: translateY(0);
    }
  }

  .msg {
    text-align: center;
    padding: 20rpx 0;
  }

  .box2 {
    width: 300px;
    height: 200px;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    z-index: 20;
  }

  .track {
    position: absolute;
    bottom: -100px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 20;
    color: #fff;
    display: flex;
    flex-direction: column;
    align-items: center;
  }

  .mask {
    position: absolute;
    z-index: 10;
    background-color: rgba(0, 0, 0, 0.55);
  }

  .mask1 {
    top: 0;
    left: 0;
    right: 0;
  }

  .mask2 {
    right: 0;
  }

  .mask3 {
    right: 0;
    left: 0;
    bottom: 0;
  }

  .mask4 {
    left: 0;
  }

  .error {
    color: #fff;
    padding: 40rpx;
    font-size: 24rpx;
    background-color: #333333;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 550rpx;
    border-radius: 20rpx;
  }

  .error .on1 {
    font-size: 30rpx;
  }
</style>
